[PATCH] Fix tree-optimization/103257: Missed jump threading due too early conversion of bool*A into bool?A:0

apinski@marvell.com apinski@marvell.com
Wed Nov 17 08:00:17 GMT 2021


From: Andrew Pinski <apinski@marvell.com>

So like many optimizations on the gimple level, sometimes it makes sense to do the
optimization early or later. In this case, creating a cond expression early causes
other optimizations to be missed.  So just disable it until canonicalize_math_p ()
is false.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR tree-optimization/103257

gcc/ChangeLog:

	* match.pd
	(((m1 >/</>=/<= m2) * d -> (m1 >/</>=/<= m2) ? d : 0):
	Disable until !canonicalize_math_p ().

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/vrp116.c: Check optimized instead of vrp1.
	* gcc.dg/tree-ssa/pr103257-1.c: New test.
---
 gcc/match.pd                               |  8 ++++----
 gcc/testsuite/gcc.dg/tree-ssa/pr103257-1.c | 11 +++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/vrp116.c     |  4 ++--
 3 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr103257-1.c

diff --git a/gcc/match.pd b/gcc/match.pd
index dc3d505..0332d87 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1781,10 +1781,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   (convert (bit_and (bit_not @1) @0))))
 
 /* (m1 CMP m2) * d -> (m1 CMP m2) ? d : 0  */
-(for cmp (gt lt ge le)
-(simplify
- (mult (convert (cmp @0 @1)) @2)
-  (if (GIMPLE || !TREE_SIDE_EFFECTS (@2))
+(if (!canonicalize_math_p ())
+ (for cmp (gt lt ge le)
+  (simplify
+   (mult (convert (cmp @0 @1)) @2)
    (cond (cmp @0 @1) @2 { build_zero_cst (type); }))))
 
 /* For integral types with undefined overflow and C != 0 fold
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr103257-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr103257-1.c
new file mode 100644
index 0000000..89f4f44
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr103257-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+void link_error(void);
+unsigned b, c;
+static short a(short e, short f) { return e * f; }
+int main() {
+  if (a(1  ^ ((0, 0) ^ 1 && b) <= b, c))
+    link_error ();
+  c = 0;
+}
+/* { dg-final { scan-tree-dump-times "link_error" 0 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp116.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp116.c
index d9d7b23..9e68a77 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/vrp116.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp116.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-vrp1" } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
 
 int
 f (int m1, int m2, int c)
@@ -9,4 +9,4 @@ f (int m1, int m2, int c)
   return e ? m1 : m2;
 }
 
-/* { dg-final { scan-tree-dump-times "\\? c_\[0-9\]\\(D\\) : 0" 1 "vrp1" } } */
+/* { dg-final { scan-tree-dump-times "\\? c_\[0-9\]\\(D\\) : 0" 1 "optimized" } } */
-- 
1.8.3.1



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